I have used both a 168 and 328 chip with no problems (beyond learning all this AVR stuff, I'm very in-experienced). So far I have successfully compiled and uploaded code from the wii-ext-to-usb. Might be a good starting point to get something running on a 168 or 328.

if you are still having troubles running your mega*p devices I recommend reading following paragraph from the V-USB wiki [1]:

8.- Don't compile for 'P' series chips - There is an issue in the driver where some interrupt tables are named in a way that isn't compatible with chips that have a 'p' after their name - i.e. ATmega168p, ATmega3280. This is tricky, since the code will compile, but just won't work. However, the 'p' series chips are binary compatible with their non-'p' cousins, so if you're working with an ATmega168p, compile for a regular ATmega168. The ATmega328p has no non-p variant, but it's binary-compatible with the ATmega168, so compile for the ATmega168. You may also try defining "USB_INTR_VECTOR" as "INT0_vect" in "usbconfig.h", or replacing "SIG_INTERRUPT0" with "INT0_vect" in "usbdrvasm.S" (around line 60 in version 20090822).

Is this forum still being used? Has this problem been solved?Anyone know whats going on?These Confirmation codes will drive everybody away they are a pain in the arse . I can't read the rotten things!!!! Taken me 5 minutes to try and read this rubbish